White spots on the skin due to sun exposure are referred to as idiopathic guttate hypomelanosis and are caused by decreased melanin in the skin, according to the American Osteopathic College of Dermatology. The condition is common in individuals with fair skin and often develops earlier in women than men.
Idiopathic guttate hypomelanosis doesn't put individuals at a higher risk for skin cancer or signify infection, according to Progressive Health. In many cases, individuals with this condition don't seek treatment, as the condition isn't considered harmful. Treatment options include tissue freezing, microdermabrasion and topical steroids. Individuals can also camouflage white spots by applying self-tanning lotion or makeup to the skin.